package com.wang.web.servlet;

//替换httpServlet，根据请求的最后一段路径来进行发放分发

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

public class BaseServlet extends HttpServlet {

    //根据请求的最后一段路径来进行发放分发
    @Override
    protected void service(HttpServletRequest req, HttpServletResponse resp)throws ServletException, IOException{
        //请求路径
        String uri = req.getRequestURI();// /brand-case/brand/selectAll

        //获取最后一段路径，方法名
        int index = uri.lastIndexOf('/');//  /selectAll
        String methodName = uri.substring(index + 1);//  selectAll

        //执行方法
        //获取BrandServlet /UserServlet 字节到对象 Class
        //谁调用我（this所在的方法），我（this）代表谁
        //this代表BaseServlet的子类（BrandServlet，，UserServlet）
        Class<? extends BaseServlet> cls = this.getClass();

        //获取方法Metod对象
        try {
            Method method = cls.getMethod(methodName, HttpServletRequest.class, HttpServletResponse.class);
            //执行方法
            method.invoke(this,req,resp);
        } catch (NoSuchMethodException e) {
            e.printStackTrace();
        } catch (InvocationTargetException e) {
            e.printStackTrace();
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        }

    }
}
